JP2003016999A - Fluorescent lamps and compact fluorescent lamps - Google Patents

Abstract

(57) [PROBLEMS] To provide a fluorescent lamp and a bulb-shaped fluorescent lamp in which the influence of ultraviolet light is reduced by suppressing the ultraviolet radiation of a bulb formed of lead-free glass with a simple configuration. SOLUTION: The fluorescent lamp 1 is made of glass substantially free of a lead component, and has a bulb 5 having an ultraviolet transmittance of 10% or more with a wavelength of 300 nm or less; mercury and rare gas sealed in the bulb 5. A gas; a phosphor layer formed on the inner surface of the bulb with a thickness of 10 μm or more; and a pair of discharge electrodes for generating a discharge in the bulb. Even in a bulb using a lead-free glass having a wavelength of 300 nm or less and an ultraviolet transmittance of 10% or more, since the phosphor layer is formed with a film thickness of 10 μm or more, the output of ultraviolet light is reduced, and the surrounding irradiation It is possible to suppress the influence of the ultraviolet irradiation on the object.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp using glass containing substantially no lead component.

[0002]

2. Description of the Related Art For example, an incandescent lamp has been used as a light source of a general lighting device, but in recent years, a fluorescent lamp has been often used from the viewpoint of life and lamp efficiency.

[0003] In particular, a compact fluorescent lamp that can be mounted as it is in a socket of a luminaire in which an incandescent lamp has been used is widely used as an alternative light source for the incandescent lamp, and its external dimensions are also described in, for example, Japanese Patent No. 3132562. It is downsized to almost the same size as an incandescent light bulb.

By the way, in the bulb-type fluorescent lamp, the bulb is bent into a substantially U-shape in order to reduce the external dimensions. In order to facilitate this bending process, the bulb is conventionally formed of lead glass having a low softening temperature. That is, the lead oxide contained in the glass has the effect of lowering the softening point of the glass and improving the workability.

However, lead is a toxic substance, and in recent years, bulbs are formed of so-called lead-free glass that does not substantially contain lead components because of problems such as environmental pollution caused by the disposal of used fluorescent lamps.

For example, Japanese Patent Laid-Open Nos. 2000-315477 and 2001-31442 disclose fluorescent lamps made of lead-free glass.

[0007]

However, when the bulb is made of lead-free glass, the UV transmittance of the bulb becomes higher than that of the bulb made of lead glass, which causes various problems.

For example, in the case of a fluorescent lamp whose bulb is made of lead-free glass, the ultraviolet rays generated by the discharge pass through the bulb without being absorbed by the bulb. It will be irradiated. Since lead-free glass transmits a relatively large amount of ultraviolet rays having a wavelength of 300 nm or less, the influence of ultraviolet rays cannot be ignored.

In particular, when a cover made of synthetic resin is provided near the bulb as in a light bulb type fluorescent lamp, the resin is deteriorated by the irradiation of ultraviolet rays and the temperature of the cover becomes 100 when the lamp is turned on. The temperature rises above 0 ° C and the resin deteriorates rapidly due to a synergistic effect with ultraviolet rays.

In order to solve this problem, it has been studied to form a protective film having an ultraviolet absorbing property on the inner surface of the bulb. However, if the protective film is formed on the inner surface of the bulb, the visible light transmittance may decrease. Moreover, since the step of forming the protective film is added, the manufacturing becomes complicated.

It has also been studied to mix an ultraviolet absorbing material such as cerium oxide (CeO) with lead-free glass. However, when an ultraviolet absorbing material is mixed with lead-free glass, the characteristics of the glass will be aged depending on the selection of the composition. There is a risk that the electrical characteristics of the glass will change and the visible light transmittance will decrease.

The present invention has been made in view of the above problems, and provides a fluorescent lamp and a bulb-type fluorescent lamp in which the ultraviolet radiation of a bulb made of lead-free glass is suppressed by a simple structure to reduce the influence of ultraviolet radiation. The purpose is to do.

[0013]

A fluorescent lamp according to claim 1, wherein the fluorescent lamp is formed of glass containing substantially no lead component, and has a UV transmittance of 10% or more at a wavelength of 300 nm or less; Mercury and a rare gas that are enclosed; a phosphor layer formed on the inner surface of the bulb with a film thickness of 10 μm or more; and a pair of discharge electrodes that cause a discharge in the bulb. And

Here, the ultraviolet transmittance means a state in which the bulb is not coated with a phosphor and is in a state of a raw tube, and can be measured by a glass piece having the same thickness as the bulb.

The lead-free glass of the present invention is a glass that does not substantially contain lead, and may contain lead as impurities.

As the valve, for example, a valve having a bent portion such as double U, triple U, or an annular shape or a shape of a straight pipe can be used, but the valve is not limited thereto.

Further, the UV transmittance of the bulb has a wavelength of 300.
A wavelength of 300 nm is defined as 10% or more when the wavelength is 300 nm or less.
This is because when the following ultraviolet ray transmittance is less than 10%, the influence of ultraviolet rays is small.

For example, when the UV transmittance of the bulb is 10% or more, the amount of UV transmission increases, and an object to be irradiated arranged near the fluorescent lamp, for example, a lighting fixture part formed of synthetic resin or This is because there is a problem that a member such as a building material formed of a material having a fading property is deteriorated.

Further, the ultraviolet ray transmittance at a wavelength of 300 nm or less is preferably 20% to 50%. The reason for defining this preferable range is that when the UV transmittance of the bulb is reduced, the transmittance of visible light also tends to be reduced, but if the UV transmittance of the bulb is within the above range, This is because it is possible to effectively suppress ultraviolet radiation, and to reduce visible light transmittance due to a decrease in ultraviolet transmittance, so that sufficient brightness can be maintained.

The phosphor layer is directly or indirectly applied / formed on the inner surface of the bulb through a protective film or the like, and the film thickness is 10 μm or more. Note that this film thickness is often not uniform on the inner surface of the bulb because the phosphor layer is applied in a slurry form. In this case, the film thickness is defined by the film thickness of the portion having the smallest film thickness.

Since the phosphor layer originally absorbs ultraviolet rays and converts it into visible light to emit light, the thickness of the phosphor layer is made larger than that of the prior art so as to enhance the ability to absorb ultraviolet rays, and the film thickness is 10 μm. Based on the above, it has been found that the output of ultraviolet light having a wavelength of 300 nm or less is reduced even in a bulb using lead-free glass.

There are no particular restrictions on the type of phosphor used in the phosphor layer, but it is preferable to use a rare earth phosphor such as a three-wavelength light emitting phosphor. As a tri-wavelength type rare earth phosphor, a blue-based phosphor having an emission peak wavelength near 450 nm is BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ , 54.
(La, Ce, Tb) PO ₄ is applicable as a green phosphor having an emission peak wavelength near 0 nm, and Y ₂ O ₃ : Eu ³⁺ is applicable as a red phosphor having an emission peak wavelength near 610 nm. However, it is not limited to these.

BaMg ₂ Al ₁₆ which emits blue light
O ₂₇ : Eu ²⁺ or green light emission (La, Ce, Tb)
Since PO ₄ has a high ultraviolet absorption ability, the fluorescent lamp of the emission color in which the amount of these phosphors used is large has the effect of suppressing the ultraviolet output even with a small film thickness of around 10 μm.

When forming a protective film on the inner surface of the valve,
As the metal oxide fine particles forming the protective film, known ones such as alumina (Al ₂ O ₃ ), silica (SiO ₂ ) or yttria (Y ₂ O ₃ ) can be used.

The rare gas sealed in the valve is preferably, for example, a simple substance of argon gas or a gas in which argon is mixed with neon or krypton.

The pair of discharge electrodes for causing discharge may be provided inside the bulb, or may be provided on the outer surface of the bulb. Examples of the pair of discharge electrodes sealed in the bulb include a hot cathode type and a cold cathode type.

In the above fluorescent lamp, the lamp current per unit cross-sectional area of the glass bulb is 200 mA.
If it is / cm ² or more, the effect becomes more remarkable. The cross-sectional area of the glass bulb means the cross-sectional area of the bulb inner space in the direction orthogonal to the bulb longitudinal direction. Also,
The lamp current is a current input to the fluorescent lamp and does not include the power consumed by the lighting circuit.

When the lighting state of the fluorescent lamp is variable, it is defined as the maximum lamp current in a range where lighting control is possible such as a high output lighting state. Therefore,
It does not include the lamp current value at the end of life or abnormal lighting.

The lamp current per unit cross-sectional area of the glass bulb (hereinafter referred to as "lamp current density") is 200 m.
This is because when it is A / cm ² or more, the amount of ultraviolet radiation increases, so that the ultraviolet absorption effect of the phosphor layer is more effectively exhibited.

According to the fluorescent lamp of claim 1, the wavelength of 30
Even if the bulb is made of lead-free glass having an ultraviolet transmittance of 0 nm or less of 10% or more, since the phosphor layer is formed to have a thickness of 10 μm or more, the output of ultraviolet rays is reduced,
It is possible to suppress the influence of the ultraviolet irradiation on the surrounding irradiation object.

A second aspect of the fluorescent lamp according to the first aspect is that the glass of the bulb is made of sodium oxide (Na).
The content of ₂ O) is 10% by mass or less.

When the Na component in the glass reacts with the mercury that has entered the glass bulb, it causes the fluorescent lamp to be colored blackish brown. In addition, N deposited on the inner surface of the valve
The component a and mercury may react with each other to form a mercury compound, which may cause a reduction in the luminous flux maintenance factor. Therefore, by controlling the content of sodium oxide in the glass of the bulb to 10% by mass or less, the above problem can be suppressed.

According to the fluorescent lamp of the second aspect, since the content of sodium oxide in the glass is 10% by mass or less, it is possible to suppress the deterioration of the luminous flux maintenance factor.

A third aspect of the present invention is the fluorescence according to the first or second aspect.
In the lamp, the glass of the bulb is 0-10 mass.
% Na₂O, 1 to 10% by mass of K₂O, 0-3% by mass
Li ₂O (however, Na₂O, K₂O and Li₂Total of O
5 to 20% by mass), 0.1 to 0.5% by mass
% Sb₂O₃And has a composition substantially containing lead
From a glass whose softening temperature is 685 ° C or less
It is characterized by

The glass using K ₂ O and Li ₂ O together with Na ₂ O as a flux has a composition substantially free of lead.
The softening temperature can be lowered to 685 ° C. or lower as compared with the conventional soda-lime glass. By applying glass with such a low softening point to the glass bulb, the heating temperature during bending can be lowered, and the deterioration of the phosphor layer due to the lowering of the heating temperature, and consequently the decrease of the total luminous flux. Can be suppressed. Furthermore, the amount of Na ₂ O is set to 10
By setting the content to be less than or equal to mass%, it becomes possible to suppress the coloring due to the Na component in the glass, and consequently, the decrease in the luminous flux maintenance factor. The amount of Na ₂ O is preferably 10% by mass or less, but in view of easiness in production and the cost of the glass material, it is preferably in the range of 1 to 11% by mass.

Here, the softening temperature is the viscosity of the glass η =
The temperature is 10 ^7.65 dPa · s. In addition, Sb ₂ O ₃
Is an essential component for applying the oxidative refining (oxidative melting) method when manufacturing a glass tube, which can further increase the total luminous flux.

According to the invention of claim 3, the amount of Na ₂ O is 1
Since the glass bulb has a softening temperature of 0% by mass or less and a softening temperature of 685 ° C. or less, the total luminous flux and luminous flux maintenance factor of the fluorescent lamp can be increased by minimizing the precipitation amount of Na component.

According to a fourth aspect, in the fluorescent lamp according to any one of the first to third aspects, the thickness of the phosphor layer is 15 to 15.
It is characterized by being in the range of 60 μm.

The larger the film thickness of the phosphor layer, the more it absorbs ultraviolet rays, but the visible light transmittance decreases. Therefore, if it exceeds a predetermined film thickness, the visible light output tends to decrease. Therefore, when the upper limit of the thickness of the phosphor layer was examined,
It was confirmed by experiments that it is possible to absorb ultraviolet rays without decreasing the visible light transmittance when the thickness is up to 60 μm. It was also confirmed by experiments that when the thickness of the phosphor layer is 15 μm or more, ultraviolet rays can be more reliably absorbed.

According to the fluorescent lamp of the fourth aspect, by setting the thickness of the phosphor layer within the range of 15 to 60 μm, the absorption of ultraviolet rays can be ensured and the visible light transmittance can be reduced. Can be suppressed.

A fifth aspect is the fluorescent lamp according to any one of the first to third aspects, wherein the thickness of the phosphor layer is 20 to 20.
It is characterized by being in the range of 40 μm.

When the film thickness of the phosphor layer is increased, the amount of the phosphor used is increased, and the cost is increased. Therefore, it may be necessary to reduce the amount used as much as possible. Therefore, when we investigated the optimum range that can absorb UV more reliably,
It was confirmed by experiments that it is possible to more surely absorb ultraviolet rays within the range of 40 μm.

According to the fluorescent lamp of the fifth aspect, when the thickness of the phosphor layer is in the range of 20 to 40 μm, the absorption of ultraviolet rays is made more reliable and the visible light transmittance is lowered. It is possible to obtain the optimum range for suppressing

A sixth aspect of the present invention is the fluorescent lamp according to any one of the second to fifth aspects, wherein the thickness of the phosphor layer is 25 μm.
The above is the feature that the phosphor layer is directly formed on the inner surface of the bulb.

A so-called protective film whose main purpose is to protect the phosphor layer is formed between the inner surface of the bulb and the phosphor layer. This protective film prevents the bulb from being colored and the visible light transmittance being lowered due to the precipitation of an alkaline component of the glass composition forming the bulb and the reaction with the phosphor layer or mercury. Further, by providing a protective film, it is possible to suppress the alkali component precipitated from the glass composition from moving to the phosphor layer side, and the alkali component reacts with the phosphor to reduce the deterioration of the emission characteristics of the phosphor, It is also possible to prevent the problem that the mercury component in the bulb becomes insufficient due to the reaction between the alkaline component and mercury to form a mercury compound and the mercury is consumed, and the bulb does not light at a desired light output.

However, when the protective film is formed, a step of coating and forming a film other than the phosphor layer in the bulb and drying is added, which complicates the manufacture of the fluorescent lamp.

Therefore, while the sodium oxide contained in the glass of the bulb used in the fluorescent lamp is 10 mass% or less, the thickness of the phosphor layer is 25 μm or more,
It is possible to obtain the same effects as when a protective film is formed, such as suppressing a decrease in luminous flux maintenance factor without providing a protective film. Therefore, it becomes unnecessary to form a protective film,
Manufacturing of a fluorescent lamp becomes easy. Further, the formation of the protective film does not cause a problem that the visible light transmittance is lowered.

According to the sixth aspect of the fluorescent lamp, the film thickness of the phosphor layer directly formed on the inner surface of the bulb is 10% by mass or less of sodium oxide contained in the glass of the bulb used in the fluorescent lamp. Since the thickness is 25 μm or more, it is possible to obtain the same effect as a fluorescent lamp having a protective film without providing a protective film, and the fluorescent lamp can be easily manufactured.

A seventh aspect of the present invention is the fluorescent lamp according to any one of the first to sixth aspects, wherein the bulb has a U-shaped bent portion, and the thickness of the phosphor layer at this bent portion is different. It is characterized in that it is formed to be smaller than the film thickness of the region.

In the case of a bulb having a U-shaped bent portion, phosphor slurry is applied to form a phosphor layer.
In this case, the phosphor layer at the bent portion has the smallest thickness.
The fluorescent lamp including the bulb having the U-shaped bent portion is often used for lighting in such a state that the bent portion is exposed to the outside from the lighting fixture, and ultraviolet rays are easily radiated from the bent portion.

According to the invention of claim 7, the thickness of the phosphor layer in the bent portion is smaller than the thickness of the other region, and the thickness of the phosphor layer in the bent portion is equal to or more than a predetermined value. By increasing the value to 1, it becomes possible to effectively suppress the output of ultraviolet rays.

According to a seventh aspect of the present invention, there is provided the bulb-type fluorescent lamp according to the seventh aspect.
A fluorescent lamp as described above; a cover for supporting the fluorescent lamp; a base attached to the cover; a lighting circuit part electrically connected to the base for lighting the fluorescent lamp, and provided in the cover. And a lighting circuit housed therein.

According to the invention of claim 8, it is possible to provide a compact fluorescent lamp having the function of the fluorescent lamp of claim 7.

[0054]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the fluorescent lamp of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic explanatory view showing an enlarged part of a bulb of a light bulb type fluorescent lamp according to the first embodiment, and FIG.
Is a front view showing the same bulb-shaped fluorescent lamp with a part cut away,
FIG. 3 is a development view showing a state of the bulb of the bulb-type fluorescent lamp in the process of being manufactured.

As shown in FIG. 2, 1 has a rated input power of 2
It is a light bulb type fluorescent lamp of 2 to 23 W, and this light bulb type fluorescent lamp 1 is provided with a cover 3 having a base 2, and a lighting circuit 4 is housed in the cover 3.

Further, an arc tube 5 as a bulb is attached to the cover 3, and a phosphor layer made of a rare-earth metal phosphor of a three-wavelength emission type having a film thickness of 10 to 30 μm is attached to the inner surface of the arc tube 5. Noble gas such as argon and mercury are sealed at a temperature of 25 ° C. and a pressure of 0.13 Pa, and a pair of electrodes 6 and 6 are sealed at both ends of the arc tube 5 by pinch seals.

The arc tube 5 is composed of four U-shaped tubes 7, 7,
7 and 7, these U-shaped pipes 7, 7, 7, 7 have, for example, a pipe outer diameter of 7 mm to 12 mm and a wall thickness of 0.7 to 1.1.
mm of lead-free glass cylindrical main valve, which is provided with a bending portion 8 molded in a U shape having a corner at an intermediate portion, and a pair of parallel mutually continuous ends of the bending portion 8. The straight pipe portions 9 and 9 are provided. When the outer diameter of the straight pipe portion 9 is d and the outer diameter of the bending portion 8 in the direction orthogonal to the radial direction of the straight pipe portion 9 is D,
1.2d ≦ Dd ≦ 1.5d, where Dd is the widest outer diameter of the corner portion of the bending portion 8 in the direction of about 45 °, which has a relationship of 0.8d ≦ D <d. Have a relationship. The outer diameter d of the straight pipe portion 9 is preferably 11 mm, and the outer diameter D of the bending portion 8 is preferably 8.5.
mm.

Since the arc tube 5 is made of lead-free glass, the ultraviolet rays generated by the discharge in the arc tube 5 are not absorbed by the bulb and easily pass through the bulb. Therefore, the wavelength 400
It transmits a relatively large amount of ultraviolet rays having a wavelength of 300 nm or less, particularly ultraviolet rays having a wavelength of 300 nm or less.

The phosphor layer has a bending portion 8 as a bent portion of 12 to 15 mm, and straight pipe portions 9 and 9 of 20 to 25 mm.
The thickness of the bending portion is the smallest. This is a film thickness difference that can be produced when the phosphor is applied in a slurry form and dried. However, since the bending portion 8 having the smallest film thickness is 10 μm or more, it is sufficient as an ultraviolet ray absorbing effect. Even if lead-free glass is used, the amount of ultraviolet rays emitted to the outside of the arc tube 5 is reduced, and the influence of ultraviolet ray emission is suppressed.

Further, the adjacent U-shaped tubes 7 are sequentially connected by the communication tube 11, and the discharge path length is 400 mm to 500 mm.
The discharge path 12 is formed. Further, in a state where the arc tube 5 is incorporated in the cover 3, the bending portions 8 of the U-shaped tubes 7 are equally spaced in a circle around a central axis whose longitudinal direction is the vertical direction of the fluorescent lamp 1. , And the straight tube portions 9 of each U-shaped tube 7 are also located at equal intervals on a predetermined circumference centered on the central axis of the fluorescent lamp 1, that is, the straight tube portions 9 of each U-shaped tube 7. Are arranged corresponding to each corner of the regular octagon. Further, each straight pipe portion 9 is formed such that the distance between the straight pipe portions 9 adjacent to each other in the circumferential direction is smaller than the outer shape of the U-shaped pipe 7.

Further, at one end of each U-shaped pipe 7, cylindrical thin pipes 15, 16, 17, 18 called exhaust pipes are provided so as to project from each other. Furthermore, inside the U-shaped tube 7, each thin tube 15,1
After being exhausted through 6, 17, 18 or a part of the thin tubes 15, 16, 17, 18, and filled with a filling gas to replace the mercury vapor pressure to 0.13 Pa or less at an ambient temperature of 25 ° C. , The thin tubes 15, 16, 17, and 18 are fused and sealed.
Note that FIG. 3 is a schematic view showing a state before the thin tubes 15, 16, 17, 18 are sealed. Then, in the thin tube 15 of the U-shaped tube 7, Bi-Sn-Hg (15
wt%) or Bi-Pb-Hg (15 wt%).

When two amalgams are enclosed, for example, when the thin tube 15 is sealed to the thin tube 15 of the U-shaped tube 7, the H content is twice as much as that of Bi-Sn-Hg (30.0 wt%).
The amalgam containing g is enclosed, and the thin tube 17 is Bi-
The Hg-less amalgam of Sn is sealed in a cooled state so that liquid mercury is not eluted. Further, by using an amalgam containing twice as much Hg as the base metal composition ratio and an amalgam containing no Hg, by repeatedly lighting the fluorescent lamp 1, it is possible to change from an amalgam containing Hg to one containing Hg less. Hg migrates to the amalgam and becomes Bi-Sn-Hg (15.0 wt%) amalgam.

This amalgam encapsulation method is particularly effective for encapsulating two Bi-In-Hg amalgams containing a small amount of Hg and having a relatively low vapor pressure. Even if there is variation, Bi-I
When n-Hg amalgam is added to each, a variation of up to 1.0 wt% occurs, but Bi-In-Hg
When using (4.0 wt%) amalgam and Bi-In Hg-less amalgam, a maximum of 0.5 wt%
Can be suppressed and the characteristics can be stabilized.

Amalgam containing Hg and Hg
By using loess amalgam, it is necessary to cool only the amalgam having Hg in order to prevent the release of Hg at the time of evacuation or the like, and it is not necessary to cool the Hg-less amalgam, so the cooling device can be simplified. it can.

The electrode 6 has a filament coil 19, and the filament coil 19 is supported by the pair of lead wires LW.

As described above, when the outer diameter of the straight pipe portion 9 is d and the outer diameter of the bending portion 8 in the direction orthogonal to the radial direction of the straight pipe portion 9 is D, 0.8d ≦ D < Since the height of the arc tube 5 in the longitudinal direction can be suppressed by setting d,
The height of the fluorescent lamp 1 in the longitudinal direction can be suppressed to be low, and the fluorescent lamp 1 can be made compact, and the length of the discharge path 12 can be increased even if the height is low, so that the efficiency of the discharge path 12 is improved. Further, even in a compact fluorescent lamp 1 having an input power to the fluorescent lamp 1 of 12 W or less, the temperature of the coldest part can be set to a predetermined temperature, so that the efficiency of the coldest part is prevented from being lowered. it can.

When the widest outer diameter of the corner portion of the bending portion 8 in the direction of about 45 ° is Dd, 1.2d ≦ Dd ≦ 1.5d. It is possible to form the coldest portion at the corner C and to prevent the mercury vapor pressure from becoming lower than necessary.

By setting the outer diameters of the straight tube portion 9 and the bending portion 8 as described above, even the low power type fluorescent lamp 1 having an input power of 12 W or less can be efficiently turned on.

In this embodiment, the case where the arc tube 5 has the four U-shaped tubes 7 has been described, but the number of the arc tubes 5 may be only one or may be two or more. Further, although the present embodiment has been described as a light bulb type fluorescent lamp, the present invention is not limited to this, and can be applied to a straight tube type or a ring type fluorescent lamp.

FIG. 4 is a front view showing a partial cross section of the structure of the ring-shaped fluorescent lamp according to the second embodiment. In the figure, 10 is a ring-shaped fluorescent lamp with a tube diameter of about 29 mm FC
It is a small-diameter ring-shaped fluorescent lamp corresponding to L32W type.
The glass bulb 50 has an outer ring diameter of 285 to 310 mm, for example, 299 mm, an outer ring diameter of 299 mm, an inner ring diameter of 266 mm, and a tube outer diameter of 15 to 18 mm, for example, 16.5 mm. The glass bulb 50 is formed to have a wall thickness of, for example, 1.0 mm in the range of 0.8 to 1.2 mm. And the ring-shaped fluorescent lamp 10 has 2
Lamp power in the range of 0-40W, 10kHz
The lamp is lit at the above high frequency, and particularly, the rated lamp power is 27 W and the high output lighting is 38 W. The model name of the ring-shaped fluorescent lamp 10 is FHC27.

A phosphor layer P is formed on the inner surface of the glass bulb 50.
Are directly formed without interposing a protective film. Further, stem portions (not shown) having electrodes are sealed at both ends of the glass bulb 50. In the glass bulb 50, a discharge gas having a predetermined pressure, that is, a rare gas such as argon gas, is filled with mercury through an exhaust pipe (not shown) in the stem portion after the exhaust process, and then the exhaust pipe is sealed. To be done. After completion of this sealing step, a hollow cylindrical base 20 having a base pin electrically connected to the electrodes is attached so as to straddle both ends of the glass bulb 50, thereby forming the ring-shaped fluorescent lamp 10. Has been done.

The phosphor constituting the phosphor layer P is not particularly limited and various known phosphors can be used. In the present embodiment, the blue region around 430 to 460 nm and the region around 540 to 550 nm are used. Green area and 610
It is particularly effective when using a three-wavelength light-emitting phosphor having a major emission peak in the red region around 620 nm.

Various known mixed phosphors can be used also for the three-wavelength emission type phosphor, for example, divalent europium- and manganese-activated aluminate phosphors, divalent europium-activated halophosphate phosphors. A blue or blue-green emitting phosphor such as a phosphor, a trivalent europium-activated yttrium oxide phosphor, a trivalent europium-activated yttrium oxysulfide phosphor or other red emitting phosphor, and a rare earth-based green emitting phosphor. A three-wavelength white light-emitting phosphor mixed with is used. In particular, a divalent europium-activated barium-magnesium-aluminum oxide phosphor (BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ) mainly emitting in the blue region
Since the ultraviolet light is efficiently absorbed, it is possible to reduce the amount of the ultraviolet light emitted to the outside of the bulb 50 by increasing the usage amount. In the case of a three-wavelength emission type fluorescent lamp, the amount of this blue phosphor used is 1 for the entire phosphor layer.
It is preferable to mix 8% by mass or more. In particular, when the green light emitting phosphor is mixed in an amount of 25 to 45% by mass, it is preferable to use the blue phosphor in a mixture of 25% by mass or more (more preferably 30% by mass or more) because of the emission color of the fluorescent lamp. It is suitable.

Next, a method for manufacturing the annular fluorescent lamp 10 of this embodiment will be described. First, for example, a phosphor coating solution in which a three-wavelength light-emitting phosphor is dispersed in an organic solvent or an aqueous solvent together with a binder is directly applied to the inner surface of a straight tube type glass bulb (glass tube), and this coating film Is baked at a temperature of, for example, 500 to 650 ° C. to form the phosphor layer P. Next, a straight glass tube having the phosphor layer P formed thereon is heated to 70 ° C. or higher, which is higher than the softening temperature of the glass constituting the glass tube.
The glass bulb 50 is obtained by heating to 0 to 750 ° C. to soften it, winding the softened glass tube around a drum or the like, and processing it into a single ring.

After bending the glass bulb 50, the residual heat during bending is used (at a temperature of about 300 to 500 ° C.).
The inside of the glass bulb 50 is exhausted. In this way, since it is not necessary to reheat the glass bulb 50 for exhausting, the amount of Na component precipitated from the glass bulb 50 can be suppressed.

After this exhaust process, mercury and a desired rare gas are filled, and then an exhaust pipe (not shown) provided at the end of the glass bulb 50 is sealed. The mercury sealed in the glass bulb 10 may be sealed in a liquid state, but in order to reduce excess mercury, it is preferable that the mercury is sealed by granular pellets as a mercury releasing structure. This granular pellet can be made of a zinc-mercury alloy having a diameter of about 0.5 to 3 mm. By encapsulating the granular pellet, the amount of mercury enclosed in the bulb 1 is reduced to about 6 mg. be able to.

Glass bulb (glass tube) as described above
The annular glass bulb 50 formed by directly forming the phosphor layer P without forming a protective film on the inner surface of the
1% by mass Na ₂ O, 1-10% by mass K ₂ O, 0-3% by mass Li ₂ O (provided that Na ₂ O, K ₂ O and Li ₂ O
In the range of 5 to 20 mass%), 0.1 to 0.
It is composed of glass having a composition containing 5% by mass of Sb ₂ O ₃ and containing substantially no lead and having a softening temperature of 685 ° C. or lower (hereinafter referred to as low softening point alkali glass). . The content of Na ₂ O is set within the range of 1 to 11% by mass from the viewpoint of production and material cost. However, if these restrictions are not satisfied, the content of Na ₂ O may be 0 to 10% by mass. Good.

The low softening point alkali glass using K ₂ O and Li ₂ O together with Na ₂ O as a flux has a composition substantially free of lead and has a softening temperature of 685 ° C. as compared with conventional soda lime glass. It can be reduced to: By using a glass bulb made of glass having such a low softening point, it is possible to lower the heating temperature during bending, and the thermal deterioration of the phosphor layer based on the lowering of the heating temperature,
As a result, it becomes possible to suppress the reduction of the total luminous flux. Further, since the amount of Na ₂ O can be set to 11% by mass or less, it is possible to suppress the coloring caused by the Na component in the glass, and thus the decrease in the luminous flux maintenance factor.

As the glass constituting the ring-shaped glass bulb 50, more specifically, 60 to 75% by mass of SiO ₂ and A
l ₂ O ₃ is 1 to 5 mass%, Na ₂ O is 1 to 11 mass%, K ₂
O is 1 to 10% by mass, Li ₂ O is 0 to 3% by mass, Na ₂ O
+ K ₂ O + Li ₂ O 5 to 20% by mass, CaO 0 to 3% by mass, MgO 0 to 2% by mass, BaO 1 to 10% by mass, SrO 0.5 to 10% by mass, CaO + MgO + B
aO + SrO is 4.5 to 16% by mass, B ₂ O ₃ is 0 to 3% by mass, ZnO is 0 to 3% by mass, and Sb ₂ O ₃ is 0.1 to 0.
It is preferable to use a glass composition having a composition of 5 mass% and a softening point of 650 to 685 ° C.

In the low softening point alkaline glass having the above glass composition, SiO ₂ is a glass network forming component, and the content thereof is in the range of 60 to 75% by mass.
If the amount of SiO ₂ is less than 60% by mass, the chemical durability of the glass will decrease, while if it exceeds 75% by mass, the meltability and workability of the glass will deteriorate.

Al ₂ O ₃ contributes to homogenization of glass and improvement of chemical durability, and the content thereof is in the range of 1 to 5 mass%. If the amount of Al ₂ O ₃ is less than 1% by mass, phase separation will occur in the glass and molding will be difficult, while if it exceeds 5% by mass, striae will occur and it will be difficult to obtain a homogeneous glass. Further, the devitrification property may be increased.

Na ₂ O, K ₂ O and Li ₂ O act as a flux, and contribute to the improvement of the meltability of the glass and the reduction of the softening temperature. Particularly, in the present invention, the amount of Na ₂ O at which the softening temperature becomes high is reduced to 11 mass% or less, and the contents of K ₂ O and Li ₂ O are increased accordingly. As a result, the softening temperature of the glass used for the ring-shaped glass bulb 1 can be lowered to 685 ° C. or lower.

In order to obtain the effects as described above, K ₂ O and Li ₂ O are preferably contained in a total amount of 4% by mass or more. Further, the amount of K ₂ O is individually set to 1% by mass or more, and the amount of Li ₂ O is set in consideration of the amount of K ₂ O. Further, the total amount including the _{Na 2 O (Na 2 O +} K 2 O + Li 2 O) is 5 mass% or more. When the total amount of the flux is less than 5% by mass, the viscosity becomes high, the meltability is lowered, and the softening temperature is also raised. Note that Na ₂ O is contained in an amount of 1% by mass or more in order to obtain the function as a flux.

In addition, Na ₂ O, K ₂ O and Li
₂ O also has the effect of adjusting the thermal expansion coefficient of glass, and in order to obtain an appropriate thermal expansion coefficient, the total amount of them is 20% by mass.
Below. If the total amount of Na ₂ O, K ₂ O and Li ₂ O exceeds 20% by mass, the coefficient of thermal expansion becomes too high and the chemical durability decreases. Individually, the amount of Na ₂ O is 11 mass% or less, the amount of K ₂ O is 10 mass% or less, and Li ₂
The amount of O is 3 mass% or less. When the amount of Na ₂ O exceeds 11% by mass, the softening point rises and the thermal expansion coefficient becomes too high. Similarly, when the amounts of K ₂ O and Li ₂ O exceed the above upper limits, the coefficient of thermal expansion becomes too high.

The total amount of Na ₂ O, K ₂ O and Li ₂ O is more preferably in the range of 12 to 19% by mass. Regarding the content of each component, the amount of Na ₂ O is 6 to 1
0 mass% range, the amount of K ₂ O is 5-9 mass% range, L
It is more preferable that the amount of i ₂ O is in the range of 1 to 2% by mass. By applying such a flux composition, it becomes possible to further lower the softening temperature of the glass.

BaO is a component that imparts high electrical insulation to glass, and its content is in the range of 1 to 10 mass%. If the amount of BaO is less than 1% by mass, sufficient electric insulation cannot be obtained, while if it exceeds 10% by mass, corrosion of the molten furnace material becomes remarkable, and defective spots increase. SrO is B
Like aO, it contributes to the improvement of electric insulation and the content thereof is in the range of 0.5 to 10 mass%. When the amount of SrO is less than 0.5% by mass, sufficient electric insulation cannot be obtained, while 1
The devitrification tendency exceeding 0 mass% is strengthened and the raw material cost is increased. The amount of SrO is more preferably 8% by mass or less.

CaO and MgO contribute to the improvement of the durability of glass, but their contents are 3% by mass respectively.
If it exceeds (CaO) and 2% by mass (MgO), devitrification of the glass tends to occur. Therefore, the content of each of them is set to be equal to or less than the above upper limit value.

The above-mentioned BaO, SrO, CaO and M
gO has the effect of increasing the electrical insulating properties of the glass as a whole, and the total amount (BaO + SrO + CaO + Mg)
O) is in the range of 4.5 to 16% by mass. If the total amount of these is less than 4.5% by mass, the electrical insulating property required for the glass bulb 1 cannot be obtained, while if it exceeds 16% by mass, the crystallization tendency of glass increases.

A small amount of B ₂ O ₃ has the effect of improving the meltability, but if its content exceeds 3% by mass, the chemical durability of the glass will deteriorate and weathering may occur on the surface during long-term use. There is. ZnO has an effect of suppressing volatilization at the time of melting B ₂ O ₃ and an alkaline component, but if the content exceeds 3% by mass, devitrification becomes strong.

Sb ₂ O ₃ is an essential component for applying the oxidative melting method when the glass tube used for the ring-shaped glass bulb 1 is manufactured, and its content is 0.1 to 0.5 mass. %
The range is. If the amount of Sb ₂ O ₃ is less than 0.1% by mass, the fining action becomes insufficient, while if it exceeds 0.5% by mass, the luminous flux maintenance factor decreases.

Fe in the above glass composition₂O₃Contains
It is also possible to make it. In this case, Fe₂O₃ Is the glass
Although it is a component that is slightly contained in the raw material from the beginning,
It may be mixed for the purpose of adjusting the transmittance of glass.
The content is 0.01 to 10,000 in terms of ferric dioxide.
The range is 0.05% by mass. Fe₂O₃The quantity is 0.01 quality
If the amount is less than%, a glass material with high purity is required.
The cost will increase, while exceeding 0.05 mass%
If so, the visible light transmittance of the glass decreases.

Next, the operation of the second embodiment will be described. The arc tube 5 is made of lead-free glass having the above composition, and particularly the content of Fe ₂ O ₃ is 0.05% by mass in terms of ferric dioxide.
Because of the following, the ultraviolet rays generated by the discharge in the arc tube 5 are not absorbed by the bulb and easily pass through the bulb. In particular, it transmits a relatively large amount of ultraviolet rays having a wavelength of 300 nm or less.

However, the ring-shaped fluorescent lamp of the second embodiment
10 is the sodium oxide contained in the glass bulb 50 11
Since the thickness of the phosphor layer is 25 μm or more while the mass% is less than or equal to, the amount of ultraviolet rays radiated to the outside of the glass bulb 50 can be reduced, and a reduction in the luminous flux maintenance rate can be suppressed without providing a protective film. It is possible to obtain the same effect as when the film is formed.

Further, since the glass constituting the ring-shaped glass bulb 50 has a low softening point, it is possible to suppress the thermal deterioration of the phosphor layer P at the time of bending, and thus the ring-shaped glass using the conventional soda-lime glass can be suppressed. The total luminous flux can be improved as compared with a fluorescent lamp. Furthermore, N in the ring-shaped glass bulb 1
Since the amount of the a component is reduced, coloring of the fluorescent lamp due to the reaction between the Na component and mercury is suppressed, and thus the luminous flux maintenance factor of the ring fluorescent lamp 1 can be increased. That is, it is possible to provide the ring-shaped fluorescent lamp 1 having improved lamp characteristics and life characteristics. Therefore,
The formation of the protective film is unnecessary, and the manufacture of the fluorescent lamp becomes easy. Further, the formation of the protective film does not cause a problem that the visible light transmittance is lowered.

In the above-mentioned embodiment, the case of applying to the small-diameter annular fluorescent lamp has been described, but the present invention is not limited to this, and the tube outer diameter is 29.5 mm,
It can be applied to a conventional ring fluorescent lamp using a 1.2 mm thick glass bulb, or may be a general fluorescent lamp using a straight tube glass bulb.

EXAMPLES Next, specific examples of the present invention and evaluation results thereof will be described.

First, SiO ₂ is 72.0 mass%, Al ₂ O
₃ is 3.5 mass%, Na ₂ O is 8.0 mass%, K ₂ O is 3.0 mass%, Li ₂ O is 2.0 mass%, and CaO is 1.
0 mass%, MgO is 0 mass%, BaO is 6.0 mass%,
SrO 1.0% by mass, B ₂ O ₃ 2.0% by mass, ZnO
After melting a glass composition having a composition of 1.3% by mass and Sb ₂ O ₃ of 0.2% by mass based on an oxidative melting method,
A glass tube was produced according to a conventional method. The softening temperature of the above glass composition is 580 ° C.

The above glass tube (outer diameter of 10.1 mm,
U with a wall thickness of 0.8 mm and a pipe length of 140 mm)
After forming the letter shape, a phosphor coating solution containing a three-wavelength phosphor in which a blue phosphor, a green phosphor, and a red phosphor are mixed to have a correlated color temperature of 6700K is applied, and the thickness of the bent portion is changed. 1
A phosphor layer was formed by drying and baking according to a conventional method so as to have a thickness of 2 to 15 μm. Then the glass tube
After joining together, electrodes were sealed on both ends by pinchles.

Next, mercury was enclosed together with argon gas in the glass bulb, and finally the exhaust pipe was sealed to obtain the desired fluorescent lamp.

On the other hand, a fluorescent lamp of a comparative example manufactured by the same process except that the same glass tube as in this example was used and the thickness of the bent portion was about 8 μm.

The amount of ultraviolet radiation of the fluorescent lamps of Examples and Comparative Examples thus obtained was measured, and it was found that the fluorescent lamps of Examples had an effect that ultraviolet rays having a wavelength of 300 nm or less had almost no effect on the irradiated object (0. 0001W / 1000l
However, in the fluorescent lamp of the comparative example,
It exceeded 0001W / 1000lm.

FIG. 5 is a graph showing the results of measuring the amount of UV radiation at wavelengths of 200 to 315 nm when the thickness of the phosphor layer was changed. The fluorescent lamp used for this measurement was formed into a ring-shaped glass bulb using glass having the same composition as the fluorescent lamp of the above-mentioned example, and the phosphor layer was formed directly on the inner surface of the glass bulb without a protective film. Ring-shaped fluorescent lamp (Model name “FCL30 / 28” with a tube diameter of about 29 mm)
Is equivalent to). A three-wavelength light emitting phosphor was used for the phosphor layer, and a phosphor layer having a film thickness varied from 20 μm to 45 μm in every 5 μm was prepared. The amount of ultraviolet light on the vertical axis is from wavelength 200 to
Intensity (mW) per 100 lm of 315 nm ultraviolet light
It shows with.

Generally, a fluorescent lamp has a wavelength of 20
UV irradiance of 0-315nm is 1.0mW / 100
It is considered that if it is lm or less, it has little influence on the surrounding irradiation object. As is clear from the graph in FIG.
When the thickness of the phosphor layer is 25 μm or more, the amount of ultraviolet rays is 1.
It was confirmed that it was 0 mW / 100 lm or less.

[0104]

According to the fluorescent lamp of claim 1, the wavelength of 3
Even if the bulb is made of lead-free glass having an ultraviolet transmittance of 00 nm or less of 10% or more, since the phosphor layer is formed to have a film thickness of 10 μm or more, the output of ultraviolet rays is reduced and the surrounding irradiation object It is possible to suppress the influence of ultraviolet irradiation on the.

According to the fluorescent lamp of the second aspect, since the content of sodium oxide in the glass is 10% by mass or less, it is possible to suppress the decrease in the luminous flux maintenance factor.

According to the invention of claim 3, the amount of Na ₂ O is 1
Since the glass bulb has a softening temperature of 0% by mass or less and a softening temperature of 685 ° C. or less, the total luminous flux and luminous flux maintenance factor of the fluorescent lamp can be increased by minimizing the precipitation amount of Na component.

According to the fluorescent lamp of the fourth aspect, by setting the thickness of the phosphor layer within the range of 15 to 60 μm, the absorption of ultraviolet rays can be made more reliable and the visible light transmittance can be reduced. Can be suppressed.

According to the fluorescent lamp of the fifth aspect, by setting the thickness of the phosphor layer within the range of 20 to 40 μm, the absorption of ultraviolet rays can be made more reliable and the visible light transmittance can be reduced. It is possible to obtain the optimum range for suppressing

According to the fluorescent lamp of the sixth aspect, while the sodium oxide contained in the glass of the bulb used in the fluorescent lamp is 10 mass% or less, the thickness of the phosphor layer directly formed on the inner surface of the bulb is set. Since the thickness is 25 μm or more, it is possible to obtain the same effect as a fluorescent lamp having a protective film without providing a protective film, and the fluorescent lamp can be easily manufactured.

According to the invention of claim 7, the thickness of the phosphor layer in the bent portion is smaller than that in the other regions, and the thickness of the phosphor layer in the bent portion is equal to or more than a predetermined value. By increasing the value to 1, it becomes possible to effectively suppress the output of ultraviolet rays.

According to the invention of claim 8, it is possible to provide a self-ballasted fluorescent lamp having the effect of the fluorescent lamp of claim 7.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an enlarged part of a bulb of a light bulb type fluorescent lamp according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway front view showing the same self-ballasted fluorescent lamp.

FIG. 3 is a development view showing a state in the middle of manufacturing a bulb of the bulb-type fluorescent lamp of the above.

FIG. 4 is a front view showing the structure of a ring-shaped fluorescent lamp according to a second embodiment of the present invention in a partial cross section.

FIG. 5 is a graph showing the results of measuring the amount of ultraviolet radiation when the thickness of the phosphor layer was changed.

[Explanation of symbols]

1, 10 ... Fluorescent lamp, 2, 20 ... Base, 3 ... Cover,
4 ... Lighting circuit, 5, 50 ... Bulb or arc tube, 8 ... Bending section as bent section, 9 ... Straight tube section, 12 ... Discharge path

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // F21Y 103: 025 F21S 5/00 B (72) Inventor Yuichi Sakakibara 4-3, Higashishinagawa, Shinagawa-ku, Tokyo No. 1 in Toshiba Lightec Co., Ltd. (72) Inventor Kazuhisa Ogishi 4-3-1, Higashishinagawa, Shinagawa-ku, Tokyo F-Term in Toshiba Lightec Co., Ltd. (reference) 5C039 EA08 5C043 AA20 CC09 CD02 CD10 DD01 DD28 EA11 EB15 EC02

Claims (8)

[Claims] 1. A bulb formed of glass containing substantially no lead component, and having a UV transmittance of 10% or more at a wavelength of 300 nm or less; mercury and a rare gas enclosed in the bulb; A fluorescent lamp comprising: a phosphor layer having a film thickness of 10 μm or more on an inner surface; and a pair of discharge electrodes for causing a discharge in the bulb. 2. The fluorescent lamp according to claim 1, wherein the glass of the bulb has a sodium oxide (Na ₂ O) content of 10 mass% or less. 3. The glass of the bulb is 0 to 10% by mass.
Na ₂ O, 1-10% by mass K ₂ O, 0-3% by mass L
i ₂ O (however, the total amount of Na ₂ O, K ₂ O and Li ₂ O is in the range of 5 to 20% by mass), 0.1 to 0.5% by mass
_3. The fluorescent lamp according to claim 1 or 2, wherein the fluorescent lamp is composed of glass having a composition containing Sb ₂ O ₃ and containing substantially no lead and having a softening temperature of 685 ° C. or lower. 4. The fluorescent lamp according to claim 1, wherein the thickness of the phosphor layer is in the range of 15 to 60 μm. 5. The fluorescent lamp according to claim 1, wherein the thickness of the phosphor layer is in the range of 20 to 40 μm. 6. The film thickness of the phosphor layer is 25 μm or more,
6. The fluorescent lamp according to claim 2, wherein the phosphor layer is directly formed on the inner surface of the bulb. 7. The bulb has a U-shaped bent portion, and is formed such that the film thickness of the phosphor layer at this bent portion is smaller than the film thickness of other regions. The fluorescent lamp according to any one of claims 1 to 6. 8. The fluorescent lamp according to claim 7, a cover for supporting the fluorescent lamp, a base attached to the cover, and a lighting circuit electrically connected to the base for lighting the fluorescent lamp. And a lighting circuit housed in the cover.